1. Field of the Invention
This invention relates to a centering device for locating the center of a workpiece and for aligning the center of a workpiece with the center axis of the spindle of a manufacturing machine such as a drill press and the like.
2. Description of Prior Art
As of this date the inventor is not aware of any prior art that can be considered obvious or similar to the present invention.
A commonly accepted practice in most machine shops for locating the center of a workpiece is marking the workpiece with reference lines as shown in the blue print, on a surface plate by means of a number of marking instruments including a surface gage, a height gage, a scriber etc. As soon as the work piece is marked with reference lines, the center point is further marked with a center punch, and then the work piece is mounted onto the worktable with suitable clamping means such as vise for drilling or cutting.
For mass production jigs and fixtures are a known means for aligning a work piece in a predetermined position with the center axis of the spindle of the manufacturing machine, but because of the high cost of jigs and fixtures, in the case of small quantity jobs the alignment of the center axis is usually done by visual inspection with or without an optical instrument.
Such common practices for locating and aligning a center position with the center axis of the spindle of a manufacturing machine have such shortcomings as requiring skill in the marking process, extra handling of the work piece in the marking process, inaccuracy of visual inspection in the alignment process, and high cost for optical instruments.